Engine starter



Nov. 6, 1934. J. A. CHARTER ENGINE STARTER Origifial Filed June 8, 1929 Patented Nov. 6, 1934 UNITED STATES PATENT OFFICE ENGINE STARTER James- A. Charter,

Charter Drive, Inc., of Illinois Original application Chicago, 111., assignor to Chicago, 111., a corporation June 8, 1929, Serial No.

13 Claims.

My invention relates generally to engine starters and particularly to starters for internal combustion engines of automobiles and the like.

The present invention is a division of my co-pending application, Serial No. 369,392, filed June 8, 1929.

Certain of the functional characteristics of my present invention bear relation to starters of the type disclosed in my Patents Nos.

m 1,554,623 and 1,682,368 and my co-pending application, Serial No. 343,718, filed March 1, 1929, in that my present invention contemplates the provision of a starter in which a driving pinion is adapted to be moved into engagement with M the fly-wheel or driving gear of the engine in response to relative movement between a helical spring and a tracker which is positioned between the convolutions of said spring. The present invention however relates to certain advantageous my structural features and novel arrangement of cooperating parts which are not disclosed in my aforementioned application and patents.

One of the primary objects of'my present invention is to provide a starter mechanism of the type set forth above, in which a helical spring or tracker cooperates with a companion helical spring to effect the automatic longitudinal shifting of the driving pinion toward and away from the gear of an internal combusgm tion engine.

Still more specifically, it is an object of my invention to provide an engine starter, as set forth above, in which one of said helical springs is connected at one extremity with the pinion, and the other extremity of said spring is adapted to abut an extremity of the other helical spring when said springs establish a driving connection.

Another object of my invention contemplates the provision of a starter, as above set forth, 4 in which said springs are provided at their free extremities with hook portions which are adapted to engage each other when the driving pinion meshes with the driving gear.

The foregoing and numerous other objects and advantages will be more apparent from the following detailed description when considered in connection with the accompanying drawing, wherein- Figure 1 is a side elevational view of a starting device representative of one embodiment of my invention, the same being shown for purposes of illustration in association with a fragmentary portion of a driven gear, such as a fiy-wheel gear, the starting motor being indigg cated by dotted lines; and

"and an annular member or collar 18 is a Figure 2 is a view similar to Figure 1, disclosing the driving pinion meshing with the driven gear.

Referring now to the drawing more in detail wherein like numerals have been employed to designate similar parts throughout the various figures, it will be observed that one embodiment of my invention comprises a shaft 10 and a driving unit longitudinally reciprocable upon said shaft, said unit being designated generally by the numeral 12. This unit 12 includes a pinion proper 14 and an annular section or shoulder 16 which is rotatable with the pinion. Encircling the shaft 10 between the section 16 pair of cooperating, coiled springs denoted generally by the numerals 20a and 20b. The collar 18 is preferably secured to the shaft 10 by means of a suitable screw 22. 1

One extremity of the spring 20a is provided with a hook 24a, which is mounted in a T slot '26 provided in the collar 18. The opposite extremity of the spring 20a is provided with a hook portion 28a, which is adapted when the springs 20a and 20b occupy the position shown in Figure 2, to interlock with a companion hook portion 281) of the spring 20b. The opposite extremity of the spring 20b is provided with a hook portion 24b which is secured within a T- shaped slot 30 provided in the pinion section 16.

It will be observed that a spiral way 32a presented between the convolutions of the coil 20a, is equal in width to the width of the hook 28b of the spring 20b. Likewise, a spiral or helical way 32b presented between the convolutions of the spring 20b, is equal in width to the hook portion 280. Thus one spring is adapted to be screwed into and out of association with respect to the other. When the springs have been screwed together, as shown in Figure 1, the hook portion 28b of the spring 20b engages an abutment or projection 34 carried by the shaft .10, and the driving member or pinion 14 is in its retracted position out of operative association with a driven gear 36. In the drawing I have diagrammatically indicated an electric starting motor 38 by dotted lines, and it will be apparent that thismotor serves to impart rotation to the shaft 10.

Assume that the parts occupy the position shown in Figure 1, and that rotation is suddenly imparted to the shaft 10 by the motor 38 so as to rotate said shaft in a clockwise direction, as viewed from the left, Figure 1. This sudden rotation will effect initial relative rotation beno tween the coiled springs 20a and 20b so as to cause the spring 20b and the driving pinion connected thereto to be moved axially toward the driven gear 36. When the pinion is moved forwardly to the position shown in Figure 2, the hook portions 28a and 28b of the springs interlock, thereby establishing a driving connection between the collar 18 and the pinion 14.

When the driven gear 36 has been rotated sufliciently to start the engine with which it is associated, and the peripheral speed thereof is in excess of the peripheral speed of the driving pinion 14, said pinion will be rotated relative to the shaft 10, thereby causing the helical spring 201) to be screwed within the companion spring 20a. Thus the driving pinion is automatically shifted to its retracted or disengaged position shown in Figure 1. The engagement of the hook portion 28b with the abutment 34 arrests relative axial movement between the parts.

From theforegoing it will be apparent that my invention provides a novel arrangement of combined helical springs for use in connection with engine starters. The advancement of the pinion 14 toward the gear 36 takes place very suddenly, and by having the double spring arrangement described above, an initial yielding action between the springs takes place as the hook portions 28a and 282) are moved into engagement with each other. However, the springs are made sufficiently rigid so as to establish a positive driving connection between the shaft 10 and the pinion 14 after the initial yielding thereof has taken place. Obviously other types of interlocking springs, as well as other means for arresting the inward movement of the spring connected with the driving pinion, may be provided without departing from the spirit and scope of my present invention. It will also be apparent that by employing my improved yieldable or spring arrangement, the" pinion is yieldably urged forwardly into mesh with the gear 36. Thus, if the faces of the pinion teeth should abut the faces of the gear driven thereby as said pinion is urged toward the gear, the yieldable connection or helical spring arrangement will serve as a cushioning means until the proper meshing of the pinion and gear teeth takes place.

It will be noted that a split abutment ring 40 is carried by the shaft 10 to prevent the forward creeping of the pinion from the position shown in Figure 1. The specific structureof this ring does not form a part of the present invention, except as it enters into the general combination of the other elements. Therefore, said ring is not shown in detail. It will be sufficient to state that this ring, while it will prevent the forward creeping of the pinion 14, will also permit said pinion to advance into mesh with the gear 36 when the motor 38 is activated.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an engine starting device of the class described, a drive shaft unit, an engine driving member on said unit for both longitudinal movement and rotary movement, said member being adapted, when properly positioned, to operatively engage an engine part to be driven, a coiled spring encircling said drive shaft unit and affixed to said engine driving member, a coiled actuating member supported externally of said coiled spring upon said drive shaft unit and adapted to be positioned between the convolutions of said spring, whereby said engine driving member may be moved into and out of operative association with the engine part to be driven, and abutment means for establishing driving connection between said coiled spring and actuating member.

2. In an engine starting device of the class described, a drive shaft unit, an engine driving member on said unit for both longitudinal movement and rotary movement, said member being adapted, when properly positioned, to operatively engage an engine part to be driven, a coiled spring encircling said drive shaft unit and affixed to said engine driving member, a second coiled spring threaded within the first coiled spring, one extremity of said second spring being affixed to the drive shaft unit, whereby said engine driving member may be moved into and out of operative association with the engine part'to be driven in response to the relative shifting of said coiled springs, and abutment means for establishing driving connection between said coiled springs and actuating member.

3. A starter for internal combustion engines comprising a rotatable driving member, a rotatable driven member, a pair of helical springs with the convolutions of one spring threaded into the convolutions of the other spring, the

outer end of one spring being fixedly connected to said driving member and the outer end of the other spring being fixedly connected to said driven member, and coacting means carried by the inner ends of said springs for forming a resilient driving connection between said driving member and driven member.

4. Means for transforming rotary into longitudinal movement comprising a rotary driving element, a reciprocable driven element, coaxial spiral springs between said members and fixed at one end to each of said members respectively, the free ends of said springs being coiled together, and coupling means for establishing driving connection between said spiral springs.

5. In a mechanical movement, a driving shaft, a driven pinion member slidably mounted on said shaft, a spiral spring on said shaft and having one end fixed thereto, a similar spiral spring having one end fixed to said pinion member, the turns of said springs being normally spaced apart and the free ends of said springs being threaded into each other whereby relative rotation between the springs causes the driven member to be removed along the shaft, and means for rendering the springs operable as a yieldirlilgfgonnection between the pinion and driving s a 6. A mechanical movement comprising a smooth driving shaft, a pinion slidably mounted thereon, a pair of springs loosely coiled together on said shaft and fixedly attached at one end to said'shaft and pinion respectively, whereby rotation of the shaft and its spring causes the pinion spring and the pinion to slide along the shaft, means for rendering the springs operable tached to the driving shaft and to the driving gear, said resilient members being intermeshed and means for rendering the resilient members operable as a yielding driving connection between the driving gear and the driving shaft.

8. An engine starter drive including a power member, a driving member adapted to be moved into and out of engagement with a member of the engine to be started, and means for actuating said driving member from said power member including a yielding spiral member anchored to said power member, a cooperating yielding spiral member anchored to said driving member and inter-threaded with said first yielding spiral member, and means for connecting the adjacent ends of said spiral members to prevent disconnection thereof.

9. In an engine starter drive, a rotary shaft, a driving pinion adapted to be shifted into and out of mesh with a gear on the engine to be started, a spring thread anchored at one end to the pinion, a spring thread anchored at one end to the shaft, the free ends of the springs being inter-threaded whereby relative rotation thereof moves the pinion into and out of mesh with the engine gear, the free ends of said springs being formed with axially extending hooks adapted to engage and couple the springs together for positioning and driving the pinion.

10. In a starter drive, a shaft, a coiled spring encircling said shaft and fastened thereon, a pinion mounted freely on said shaft, a second coiled spring carried by said pinion, said spring surrounding said shaft and intertwining said first named spring, and means on the free end of 'each of said springs for engagement one with the other when the starter shaft is operated.

11. In a starter drive, a shaft, a pair of substantially similar coiled springs on said shaft, a pinion mounted freely on said shaft, one end of said springs being fastened to said shaft, and the other of said springs to the pinion, and means on the free end of said springs for interengagement to thereby take the torsional, load in starting the motor.

12. In a starter drive, a shaft, a spring coiled about said shaft and fastened thereto, a second spring mounted longitudinally on said shaft to intertwine therewith when the starter becomes effective, and means for rendering said springs operable as a yielding driving connection between the shaft and a member to be started.

13. In an engine starting device, a drive shaft unit, an engine driving member on said unit for both longitudinal and rotary movement, said member being adapted in one shifted position to operatively engage an engine part to be driven, a coiled spring structure on said unit having an extremity thereof connected with the engine driving member, said spring structure including a pair of spring elements, at least one of which is movable as a unit with the driving member, abutment means for establishing yieldable driving connection between said coiled spring struc ture and said drive shaft unit, and means r0- tatable with the drive shaft unit and adapted to be engaged by one extremity of the spring structure to limit the movement of the pinion as it shifts out of engagement with the engine part to be started.

JAMES A. CHARTER. 

